Wireless telegraphy.



W. 0. WOODLAND.

WIRELESS TELEGRAPHY.

APPLICATION FILED 001224, 1912.

1 1 14,840, Patented Oct. 27. 1914.

zjd/ffll/aaww 1 upon closinz-frequency UNITED STATES P ENT OFFICE.

WILLIAM c., woonnnim, or WARREN, OHIO, ASSIGNOR TO PACKARD ELECTRIC com- PANY, OF WARREN,

OHIO, A CORPORATION OF OHIO.

WIRELESS TELEGRAPHY.

Specification of Letters Patent.

Patented Oct. 27, 1914.

To all whom it may concern. v I

Be it known that I, WILLI C. W'ooo- LAND, of Warren, in the county of Trumbulland State of Ohio, have invented certain new and useful Improvements in lVireless Telegraphy; and I do hereby declare the following to be a full, clear. and exact descriptionof the invention. such as will en able others skilledin the art towhich it appertains tomake anduse the same.

Thejprimary object of this invention is to increase the group frequency or pitch of the tone heard at the receiving station of a wireless-telegraph system. This I accomplish by a high obtained by dividing up a multi-phase 'al-.

-group frequency, ivhich is ternating current into a. plurality of intermediate 1phases and taking off the current from eac by a rotary elephase successively of each phase ment, the oscillating circuit being opened before the next one becomes active.

each signal and each phase 18 tuned alike.

All the phases are made use of for The discharges being equal in intensity and following each other at regular intervals will produce a 'smooth tone easily distinguishable'through atmos heric disturbances.

In the accompanying rawings, Figure l I is a diagrammatic view, of the apparatus.

Fig. 2 shows diagrammatically a wave representing single phase current. Fig. 3 rep resents the multiphase currents utilized by my invention.

In the art of wireless telegraphy it has heretofore been common to roduce the electrical oscillations by disc arging a condenser .througha spark gap and a portion of a. helix connected di..ectly or indirectly to an aerial, the condenserbeing. charged by exciting a transformer connected thereto 7 the transmission key. Twice each cycle t e condenser discharges through the spark gap and helix, creating a highcurrent, as is well known. The wave length .of the high-frequency currents radiated by the aerial depends upon the value of the helix pitch s received pends on the turn depends and condenser, but their at the receiving station dcgroup frequency, and this in upon the frequency of the source of electrical supply. If this is 60 Heretofore it has been sought to break up the group fre uency in an effort to get more than one disc large for each one half cycle of current supply, but even if more than one discharge is produced such discharges manifestly cannot be equal in intensity. 'But ac cording to my invention this difficulty is overcome, and a resultant high group froquency, producing a smooth note, is obtained. For this purposeI use a multiphase alternating current which is tapped to give me the number of phases I preferably six. With the latter I obtain a group frequency of 720 per second when excited with three-phase cycle current. The circuit of each phase comprises a separate transformer, condenser, and spark terminal. A rotary element is designed to rotate in proximity to the separate sparking terminals, and if rotated in synchronism with the alternating current, each phase will discharge when the rotating sparking element comes opposite its respective sparking point, and such rotary element should be arranged to reach this point at the instant the con' denser attains its maximum potential. The (lischargcs from all the phases are therefore picked up by the rotary element and carried through the helix and back to a point connecting all the condensers and transformers. The sending key must necessarily be arranged to operate two circuits at once.

My im'ention will be readily understood from the drawings, whcrein 1 is a multi-phase transformer from which is tapped a series of phases, preferably six in number, although the number may be increased or lessened. The multiphase current may be supplied direct from an altermating current generator having the necessary number of phases, but I prefer to use the transformer. The circuit of each phase embodies a transformer 2; a condenser 3, and a spark-gap terminal 4, the terminals for the several phases being shown as arranged on an arc of a circle in proximity to a rotating element 5 which is designed to successively come into position to allow a spark to pass between itself and each terminal. This rotary element is connected to a helix 6, which in turn is directly or inductively connected to an aerial 7, and, in

addition to a ground connection, the helix has a return connection with the transformers of the several intermediate phases. A double key 8 must be capable of operating desire, 7

two circuits of the main at once when a three phase source is used.

The present invention may be more clearly understood by reference to the diagrammatic Figs. 2 and 3. The former shows the standard representation of an ordinary 6O cycle wave. From the point a to 0 is one whole wave or cycle, and from a, to b is a half wave, the distance being 1/120 of a second. Sparks will be produced in the spark gap at approximately the crests of the waves indicated at s. As shown in Fig. 3 in addition to the wave a b a I introduce additional waves, and when the positive and negative halves of these waves are considered alike, the crests of the waves follow each other at equal intervals,.and altogether there are six times as many as there are in a pure 6O cycle current; Of course, any number of intermediatewaves are readily obtainable from a multi-phase current. I use either a three-phase ora two-phase transformer excited by a suitable dynamo as the source of supply. With a six-phase arrangement- Iobtain a group frequency of 720 per second when excited with a three phase cycle current The tone produced about corresponds to the note high F of the musical .scale.

The advantages of my invention will be readily appreciated. A high group frequency is obtained without the use of an expensive high frequency dynamo; a large number of corresponding small transformers being used, if one of them burns out it may be easily replaced without much expense, and such burning .out does not cripple the entire station. This is also true of the condensers. It will also be noted that according to my invention I obtain a number of low frequency electric discharges forming a series of discharges of higher frequency, and that by the use of. the rotary element for producing the successive discl'iarges each phase is opened before the next one becomes active, and each discharge will 1,1 new be equal in intensity and produce an easily distinguishable smooth tone.-. The use .of staticnar Y spark gaps would not accomplish this resu t satisfactorily, becausejof the indefiniteness of the point of maximum potential, and because, especially when the number of phases is large and the logarithmic decrement low, the discharges of two or more phases are likely to take place con currently. By means of the rotary sparki ing element all danger of concurrent discharges is eliminated because the circuit of each phase is always open excepting at the time for its proper discharge.

I. claim as my invention '1. In a sender for wireless multi-phase alternating current producer, and a plurality of energy-consuming vices energized by said producer in a multiphase relation to each other, and comprising each a transformer, a condenser, and a sparking terminal,'in combination with a helix common to all said devices, and a rotary element coiiperating with said sparking terminals for efiecting the successive discharge of said condensers through .the helix. i l

2. In a sender for wireless telegraph'y, a multi-phase alternating current producer, and a plurality of energy-consuming devices energized by said producer in multiphase relation to each other, and comprising each a transformer, a condenser, and a sparking terminal, in combination with a helix common to all said devices, and a rotary element cotiperating with said sparking terminals to efiect the successive discharge of each condenser through the helixat the instant of its maximum potential.

In testimony whereof, specification in the presence of two subscribing witnesses." w

' WILLIAM G. WOODLAND;

Witnessesz. v

N. A. WoLco'rr,

R. H.'SNYDER.

telegraphy, a"

I have signed this 

